Incentivised Content Sharing – What’s your take?

One of my favorite sites Design You Trust has implemented a nice little feature to encourage sharing and engagement on their site.  But I not sure how I feel about it “ethically”. I share their content anyway, but will I do that more now that I’ve seen this (I used to just follow them on RSS).

 It’s powered by PunchTab and here’s their elevator pitch

Overview
PunchTab is the world’s first instant loyalty platform that allows website owners (including bloggers), application developers and brands to create a social and mobile-enabled loyalty program for free in minutes. We have two popular products today, both of which cost nothing to use:
1.    – An ongoing loyalty program that you can use to encourage your users to visit every day, share your content on social networks and leave comments (we also have a development kit that allows you to add custom ways to earn points). Users will earn points every day for their actions and can redeem for rewards from a customizable loyalty catalogue when they earn enough points.
2.    – A one-time promotional giveaway widget that encourages your users to spread the word about your site in exchange for entries into a prize raffle.
 

Incentivised Content Sharing – What’s your take on it?